Pouch-typed battery cell comprising electrode lead having current breaking function

Patent metadata

Field	Value
Publication number	US-2018198109-A1
Application number	US-201815862029-A
Country	US
Kind code	A1
Filing date	Jan 4, 2018
Priority date	Jan 6, 2017
Publication date	Jul 12, 2018
Grant date	—

Abstract

A battery cell includes an electrode assembly and a battery case. The electrode assembly includes a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode. The battery case includes an upper case and a lower case, at least one of the upper case and the lower case being provided with a receiving part, in which the electrode assembly is mounted. One end of each of electrode tabs extending from electrode plates of the electrode assembly is coupled to a corresponding end of an electrode lead, which protrudes outward from the battery case. The electrode lead is provided with at least one notch part configured to rupture in response to expansion deformation of the battery case when the pressure in the battery cell increases to achieve the electrical cutoff of the battery.

First claim

1 . A battery cell comprising:
an electrode assembly comprising a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode; and a battery case comprising an upper case and a lower case, at least one of the upper case and the lower case being provided with a receiving part, in which the electrode assembly is mounted, wherein one end of each of electrode tabs extending from electrode plates of the electrode assembly is coupled to a corresponding end of an electrode lead, which protrudes outward from the battery case, the electrode lead is provided with at least one notch part configured to rupture in response to expansion deformation of the battery case when a pressure in the battery cell increases in order to achieve an electrical cutoff of the battery, the electrode lead is connected to one of the upper case and the lower case by fusion in a state in which a first insulative film is interposed between a portion of one surface of the electrode lead that is adjacent to the electrode assembly on a basis of the notch part and an inner surface of the one of the upper case and the lower case, and the electrode lead is connected to the upper case and the lower case by fusion in order to seal the battery case in a state in which second insulative films are interposed respectively between portions of opposite surfaces of the electrode lead that is distant from the electrode assembly on the basis of the notch part and the inner surfaces of the upper case and the lower case.

2 . The battery cell according to claim 1 , wherein the notch part is formed within a range of 10% to 50% a total length of the electrode lead from a coupling region between the electrode tabs and the electrode lead.

3 . The battery cell according to claim 1 , wherein the notch part is formed so as to have a depth equivalent to 20 to 80% a total depth of the electrode lead.

4 . The battery cell according to claim 1 , wherein the portion of the one surface of the electrode lead that is adjacent to the electrode assembly is connected to the inner surface of the one of the upper case and the lower case by fusion, and the notch part is formed in the other surface of the electrode lead.

5 . The battery cell according to claim 1 , wherein one of the second insulative films, interposed respectively between the portions of the opposite surfaces of the electrode lead that is distant from the electrode assembly on the basis of the notch part and the inner surfaces of the upper case and the lower case, is longer than the other of the second insulative films.

6 . The battery cell according to claim 5 , wherein the one of the second insulative films, which is longer than the other of the second insulative films, is located on one of the opposite surfaces of the electrode lead that is opposite the surface of the electrode lead on which the first insulative film is located.

7 . The battery cell according to claim 5 , wherein, on an assumption that a length from a position at which the notch part is formed to an end of the battery case is 1, the one of the second insulative films has a length of 0.8 to 1, the other of the second insulative films has a length of 0.7 to 0.3, and ends of the second insulative films that are distant from the notch part are located at a same position in a longitudinal direction of the electrode lead.

8 . The battery cell according to claim 1 , wherein
the second insulative films, interposed respectively between the portions of the opposite surfaces of the electrode lead that is distant from the electrode assembly on the basis of the notch part and the inner surfaces of the upper case and the lower case, have a same length, and an auxiliary insulative film is further interposed between and fused to the surface of the electrode lead in which the notch part is formed and the inner surface of the battery case so as to be located between the notch part and one of the second insulative films that is distant from the electrode assembly.

9 . The battery cell according to claim 1 , wherein each of the insulative films is a polypropylene film or a polyimide film.

10 . The battery cell according to claim 1 , wherein the electrode tabs are coupled to the electrode lead by welding.

11 . The battery cell according to claim 1 , wherein positive electrode tabs and negative electrode tabs are formed in a same direction.

12 . The battery cell according to claim 1 , wherein positive electrode tabs and negative electrode tabs are formed in opposite directions.

13 . The battery cell according to claim 1 , wherein the battery case is made of a laminate sheet comprising an outer resin layer, a metal blocking layer, and a thermally fusible resin sealant layer.

Assignees

• Lg Chemical Ltd

Inventors

• Kim Sang Hun
• Kim Yong
• Kang Min Hyeong
• Kim Cho Long
• Yu Hyung Kyun
• Lee Ji Hoon
• Choi Yong Su
• Hwang Soo Ji

Classifications

• H01M50/178

  for pouch or flexible bag cells · CPC title

• H01M50/553

  Terminals adapted for prismatic, pouch or rectangular cells · CPC title

• H01M50/55

  on the same side of the cell · CPC title

• H01M50/129

  with two or more layers of only organic material · CPC title

• H01M50/119

  Metals · CPC title